Depending on how loud your boat is ect. Example do you have a "Sideswipe exhaust" or a "Fresh Air exhaust" ext. Depending on how loud things are at the back of your boat could make a huge difference.
Personally I think the Stealth will work. I think it will be operating right at the top end of its range or close to it. Some people like to have head room in there system so I understand why people are recommending a traditional set up. I don't think you would have any problem selling a used stealth in the event you didn't like it.
It sounds like you just need some basic sound and I think the stealth would work out fine for you.
Yes my Air is a 02 and I like you don't like loud music and hardly ever turn it up!